Dynamics of vaginal microbiome in female beagles at different ages

Age-related changes in human vaginal microbiota composition have been reported, and such changes might be influenced by humidity, external stimuli, hormone levels, drug to use, and other factors. However, there is no report about the vaginal microbiota composition of female beagles at different ages. To investigate the effects of aging on the vaginal microbiota independent of other effects, we analyzed the vaginal microbiomes of 23 beagles at a wide range of ages from 1 year to 7 years old (except the 3rd year), 1-2 y were categorized into youth stage (YS), 4-5 y were categorized into middle stage (MS), and 6-7 y were categorized into elderly stage (ES) based on age. Samples were collected by scraping the vaginal mucosa of YS (n = 8), MS (n = 5) and ES (n = 10), and analyzed by 16S-rRNA gene high-throughput-sequencing. The diversity of the vaginal microbiome in female beagles was found to continuously change with age. We also found associations between age and specific members and functions of the vaginal microbiome. The metabolism of terpenoids and polyketide and the cell motility are significantly enhanced with age. Our results suggest that the proportion of Tenericutes might be a biomarker which could distinguish between YS and others.